PKCalpha Research Articles

Expression and clinical significance of PIKFYVE gene in hepatocellular carcinoma analyzed based on TCGA database and experimental validation

Objective: To investigate the expression and clinical significance of human FYVE finger-containing phosphoinositide kinase (PIKFYVE) in hepatocellular carcinoma (HCC) on the basis of cancer genome atlas (The cancer genome atlas, TCGA) database analysis and clinical samples experimental validation. Methods: Based on the data information of 424 clinical samples (including 374 cases of HCC tissues and 50 cases of nontumorous liver tissues) in the TCGA database, Cox regression analysis and Kaplan-Meier method were used to analyse the relationship between the PIKFYVE mRNA expression and the clinical characteristics, prognosis for survival of HCC patients. The relationship between the PIKFYVE gene and immune cell infiltration was examined by correlation analysis between the PIKFYVE gene and 24 immune cells. In addition, we analysed the correlation between the mRNA expression of PIKFYVE gene and RAC-alpha serine/threonine-protein kinase (AKT1), phosphatase and tensin homolog (PTEN), protein kinase C, alpha (PRKCA), inositol polyphosphate-5-phosphatase (INPP5D), phosphoinositide-3-kinase regulatory subunit 1(PIK3R1), Inositol Polyphosphate 4-phosphatase Type II (INPP4B) and phospholipase-C4 gene (PLCB4) in HCC tissues. Meanwhile, paraffin sections of highly differentiated, moderately differentiated, poorly differentiated, and nontumorous liver tissue in the Department of Pathology of the First Affiliated Hospital of Xinjiang Medical University were collected, each of which was 30 cases, and the histopathological observation was carried out by HE staining, and the expression levels of PIKFYVE and Ki67 proteins were verified by immunohistochemistry in each clinical sample. Results: The expression level of PIKFYVE gene in HCC tumours was significantly higher than that in normal liver tissues (P=0.000 2, P<0.01), and the overall survival of patients in the low PIKFYVE expression group was significantly longer than that in the high expression group (HR=1.57, 95%CI: 1.10～2.25, P=0.014). The results of Univariate Cox regression analysis showed that there was an effect of TNM stage, pathological stage, tumour status and residual tumour on Overall survival (OS) (P<0.05), and the expression level of PIKFYVE had an effect on OS survival (P<0.05); the PIKFYVE prognostic risk model score ratio was HR=1.533 (1.077-2.181, P=0.018). Multivariate Cox regression analysis showed a PIKFYVE prognostic risk model score ratio HR=1.481 (0.886-2.476, P=0.134) and an area under the Receiver Operating Characteristic curve of 0.640, which was greater than 0.5, suggesting that the PIKFYVE prognostic risk model has a predictive value in survival prediction. Correlation analysis showed that the expression level of PIKFYVE was highly correlated with immune cell infiltration and TP53 (P<0.01). The immunohistochemistry staining results showed that the expression of PIKFYVE in HCC tissues was significantly higher than that of nontumorous tissues (P<0.05), and there was a negative correlation with the degree of differentiation. Conclusion: PIKFYVE, as an independent risk factor for HCC, is expected to be developed as a clinical diagnostic biomarker for HCC, which will provide a reference for new drugs for the treatment of HCC.

Novel therapies for pediatric low grade glioma.

Current biological findings provide new insights into the genetics driving growth of low-grade gliomas in pediatric patients. This has provided new targets for novel therapies. The purpose of this paper is to review novel therapies for pediatric low-grade gliomas that have been published in the past 24 months. Low-grade gliomas are often driven by mitogen activated protein kinase (MAPK) alterations either with BRAF V600E point mutations or BRAF fusions. Current advances have also highlighted novel fusions of fibroblast growth factor receptor (FGFR), myeloblastosis family of transcription factors (MYB), meningioma 1 tumor suppressor (MN1), neurotrophic receptor kinase family of receptors (NTRK), Kristen RAS (Rat Sarcoma Virus) oncogene homolog in mammals (KRAS), Receptor tyrosine kinase ROS proto oncogene 1 (ROS1), protein kinase C alpha (PRKCA), and platelet derive growth factor receptor (PDGFR) amplification. Novel therapies have been employed and are showing encouraging results in pediatric low-grade gliomas. Current trials are underway with newer generation pan RAF inhibitors and mitogen activated protein kinase - kinase (MEK) inhibitors. Other early phase clinical trials have provided safety data in pediatric patients targeting FGFR fusion, NTRK fusion, PDGFR amplification and ROS1 mutations. Historical treatment options in pediatric low-grade gliomas have utilized surgery, radiation therapy and conventional chemotherapy. Recently greater insight into their biology has found that alterations in MAPK driven pathways are often the hallmark of tumorigenesis. Targeting these novel pathways has led to tumor control and shrinkage without the use of conventional chemotherapy. Caution should be taken however, since these treatment options are still novel, and we do not fully appreciate the long-term effects. Nonetheless a new era of targeted medicine is here.

Pulsatillic acid as a potential inhibitor of protein kinase C-alpha in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is a global health concern with a significant impact on morbidity and mortality. Small molecule inhibitors targeting genetic mutations like EGFR and ALK have shown promise in NSCLC treatment. This study focuses on Protein Kinase C-alpha (PKCα), implicated in NSCLC pathogenesis. Overexpression of PKCα correlates with advanced disease stages. Preclinical studies suggest its inhibition can suppress NSCLC cell growth. The research employs molecular docking to identify Pulsatillic acid (PA) as a potential PKCα inhibitor. ADMET predictions support PA's candidacy and PASS analysis and Swiss Target Prediction reveal its biological properties. Fluorescence-based binding assays demonstrate PA's inhibitory potency on PKCα, aligning with molecular docking findings. Cytotoxicity assays show PA's minimal impact on HEK-293 cell viability, with an IC50 of 21.03 μM in A549 cells. mRNA expression analysis in A549 cells indicates PA's potential inhibitory effect on PKCα. In conclusion, this study highlights that PA may emerge as a promising therapeutic candidate for NSCLC, emphasizing the need for further research, validation, and exploration of its translational potential. The study contributes valuable insights into NSCLC treatment strategies, emphasizing the significance of targeting PKCα.

Network Analysis and Experimental Verification of the Mechanisms of Hydroxysafflor Yellow A in Ischemic Stroke Following Atherosclerosis

Hydroxysafflor yellow A (HSYA) is derived from Carthamus tinctorius L. (Honghua in Chinese) and is used to treat cardiovascular and cerebrovascular disease. However, the mechanism by which HSYA treats ischemic stroke following atherosclerosis (ISFA) remains unclear. The targets and pathways of HSYA against ISFA were obtained using network analysis. A total of 3335 potential IFSA-related targets were predicted using the GenCards and Drugbank databases, and a total of 88 potential HSYA-related targets were predicted using the Swiss Target Prediction database. A total of 62 HSYA-related targets against IFSA were obtained. The network was composed of HSYA, 62 targets, and 20 pathways. The top 20 targets were constructed via the protein–protein interaction (PPI) network. Gene Ontology analysis revealed that the targets were involved in signal transduction, protein phosphorylation, the cytoplasm, the plasma membrane, the cytosol, zinc ion binding, ATP binding, protein kinase binding/activity, and enzyme binding. The Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that the pathways were associated with cancer, inflammatory mediator regulation of the transient receptor potential channels, and microRNA in cancer. Additionally, molecular docking indicated that HSYA mainly interacts with five targets, namely interleukin 1 beta (IL-1β), signal transducer and activator of transcription 3 (STAT3), E1A-binding protein p300 (EP300), protein kinase C alpha (PRKCA), and inhibitor of nuclear factor kappa B kinase subunit beta (IKBKB). In animal experiments, HSYA administration ameliorated the infarct size, neurological deficit score, histopathological changes, carotid intima-media thickness (IMT), and blood lipid level (total cholesterol and triglycerides). Immunochemistry and quantitative PCR showed that HSYA intervention downregulated the expression of STAT3, EP300, PRKCA, and IKBKB, and the enzyme-linked immunoassay showed reduced IL-1β levels. The findings of this study provide a reference for the development of anti-ISFA drugs.

Abstract B070: Global proteomics and phosphoproteomics profiling of prostate cancer patient derived xenografts tumors from the LuCaP series

Abstract Castration Resistant Prostate Cancer (CRPC) is a form of prostate cancer (PCa) that is resistant to androgen deprivation therapies. Resistance to these therapies leads to metastatic CRPC of adenocarcinoma (AD) origin and can transform to emergent aggressive variant prostate cancer (AVPC) which has genetic aberration features similar to neuroendocrine (NE) phenotypes. Understanding and identifying the underlying mechanisms of resistance and genetic transformations leading to protein alterations will enable us to develop novel therapeutic methods to counteract this resistance and improve outcomes for men with lethal metastatic prostate cancer. To this end, we used patient-derived xenografts (PDXs), an in-vivo clinically relevant model from advanced prostate cancer (PC) patients, to investigate the biology, identify novel protein targets and evaluate new treatment modalities. We aimed to identify known and novel protein kinase targets that might be phospho-regulated unique between CRPC, in AD and AVPC in NE. To pursue this, we applied a mass spectrometry base phosphoproteomics analysis. We processed 48 PDX samples, which included 15 non-castrated (NCR), 18 castration resistant (CR), which are the AD samples and 15 AVPC, the NE tumors. To enrich for global phosphorylated residues, we used sequential metal oxide affinity chromatography. We sequenced peptides from each sample using liquid chromatography in tandem with Orbitrap Eclipse Tribid MS and FAIMS technology for 2 hour gradients. To normalize and calibrate the LC method and to compare across all 48 runs, we spiked-in 400 femtomol of internal standards (iRT) to each sample. For peptide sequence and search analysis, we used Maxquant search algorithm. Using a &amp;gt; 0.75 probability phospho-residue cut-off and 5% FDR, we identified more than 9,700 phospho-residues. We identified RET, ASCL1, CHGA and SYP in NEPC and Androgen Receptor (AR), FOXA1, HOXB13, NKX3.1 and TACSTD2 in the adenocarcinoma PDX LuCap tumor samples, which confirms that our approach detected specific proteins already previously established. We subsequently performed a kinase substrate enrichment analysis and identified GSK-3, ERK1, ERK2, CDK5 kinases to be significantly enriched in the NE tumors while ATM kinase and PKC alpha and beta were enriched in the AD PDX tumor samples. Hierarchical clustering analysis across NE versus AD tumor samples indicated that samples within each group clustered uniquely where we observed intra and inter sample variability. We generated pathway enrichment and GSEA analysis, identified novel targets for therapeutic treatments and novel surface proteins. In conclusion, we have performed a global mass spectrometry based proteomic analysis and created an important first global phosphoproteomics and proteomics database that provides insights into the differentially regulated protein and phosphoproteins between AD and NE PDX tumors and provide a protein database source to develop new hypothesis. Citation Format: Zoi E. Sychev, Gabbrianne E. Larson, Hannah E. Bergom, Abderrahman E. Day, Megan E. Ludwig, Atef E. Ali, Eva Corey, Stephen R. Plymate, Justin E. Hwang, Justin M. Drake. Global proteomics and phosphoproteomics profiling of prostate cancer patient derived xenografts tumors from the LuCaP series [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr B070.

Abstract 29: Detection of Protein Kinase C Isoenzymes in Patients at Risk of Schistosoma Haematobium Induced Bladder Cancer

Abstract Purpose: The Detection of Protein Kinase C Isoenzymes in Patients at risk of Schistosoma haematobium induced Bladder Cancer attending University of Maiduguri Teaching Hospital (UMTH) was carried out. The study comprised of fifty six (56) patients aged ten to fifty six (10-56) years with clinical features of schistosomiasis and confirmed for the presence of S .haematobium eggs in urine samples. Methods: Twenty milliliters (20ml) of urine was centrifuged at 1000 rpm for 10 min to obtain the sediment. The supernatants were then discarded and the sediment (pellet) re-suspended for S. haematobium. A drop of the sediment were transferred to a glass slide, covered with a cover slip and examined using × 40 objective lens. The urine samples were observed for red blood cells and deposits that might contain proteins. The extraction of total urine template RNA was carried out according to Bioneer Specification and protocol; fifty six (56) of the S. haematobium samples of the patients were used. AccuPrep® Universal RNA Extraction Kit (K-3141) from Bioneer Corporation was used and one page protocol was followed for RNA Extraction. Pre- Denaturation was done for 5min at 94oC, Denaturation for 30sec at 94oC, Annealing for 30sec at 52oC, Extension for 1min at 72oC 35 cycles, Final extension for 5min at 72oC. Results: Result was run on 2% agarose gel. The study was able to investigate and detect the putative involvement of different PKC isoforms (alpha, beta, and delta) in patient with risk of schistosoma related bladder cancer. Out of the fifty six (56) Multiplex PCR Amplification of PKC Alpha, PKC Beta and PKC Delta from cDNA of extracted RNA template of S. haematobium infected urine sample investigated, only twenty seven (27) showed detection base pairs predicted size from Lane 1-9; of which PKC Alpha (325bp) has two (2) lane; PKC Beta (490bp) has seven (7) lane; and PKC Delta (404bp) has eighteen (18) lane of predicted base pair according to the cDNA size marker, some empty-zero (0) bands lanes and Unpredicted base pair band size were also seen. Conclusion: The major findings in the present study were the detection of PKC isoenzymes base pairs (band) which indicated the risk level of schistoma induced bladder cancer and stages of the patients using the analysis that proves Isoenzymes are detected by electrophoresis. Snail control, sanitation, avoid contacts with bullinus species and focus on early detection and diagnosis of patients infected with S. haematobium. Citation Format: Zanna Abdulsalam, Adamu Inuwa, Sambo Bello Zailani. Detection of Protein Kinase C Isoenzymes in Patients at Risk of Schistosoma Haematobium Induced Bladder Cancer [abstract]. In: Proceedings of the 11th Annual Symposium on Global Cancer Research; Closing the Research-to-Implementation Gap; 2023 Apr 4-6. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(6_Suppl):Abstract nr 29.

Salivary protein kinase C alpha and novel microRNAs as diagnostic and therapeutic resistance markers for oral squamous cell carcinoma in Indian cohorts.

Oral squamous cell carcinoma (OSCC) is the second leading cause of cancer-related morbidity and mortality in India. Tobacco, alcohol, poor oral hygiene, and socio-economic factors remain causative for this high prevalence. Identification of non-invasive diagnostic markers tailored for Indian population can facilitate mass screening to reduce overall disease burden. Saliva offers non-invasive sampling and hosts a plethora of markers for OSCC diagnosis. Here, to capture the OSCC-specific salivary RNA markers suitable for Indian population, we performed RNA-sequencing of saliva from OSCC patients (n = 9) and normal controls (n = 5). Differential gene expression analysis detected an array of salivary RNAs including mRNAs, long non-coding RNAs, transfer-RNAs, and microRNAs specific to OSCC. Computational analysis and functional predictions identified protein kinase c alpha (PRKCA), miR-6087, miR-449b-5p, miR-3656, miR-326, miR-146b-5p, and miR-497-5p as potential salivary indicators of OSCC. Notably, higher expression of PRKCA, miR-6087 and miR-449b-5p were found to be associated with therapeutic resistance and poor survival, indicating their prognostic potential. In addition, sequencing reads that did not map to the human genome, showed alignments with microbial reference genomes. Metagenomic and statistical analysis of these microbial reads revealed a remarkable microbial dysbiosis between OSCC patients and normal controls. Moreover, the differentially abundant microbial taxa showed a significant association with tumor promoting pathways including inflammation and oxidative stress. Summarily, we provide an integrated landscape of OSCC-specific salivary RNAs relevant to Indian population which can be instrumental in devising non-invasive diagnostics for OSCC.

PRKCA Promotes Mitophagy through the miR-15a-5p/PDK4 Axis to Relieve Sepsis-Induced Acute Lung Injury.

Acute lung injury (ALI) caused by sepsis is a common respiratory critical illness with high morbidity and mortality. Protein kinase C-alpha (PRKCA) plays a protective role in sepsis-induced ALI. However, the detailed molecular mechanism of PRKCA in ALI caused by sepsis is unclear. Animal and cell models of sepsis were established by cecal ligation and puncture (CLP)-surgery and lipopolysaccharide (LPS)/interferon-gamma (IFN-γ) treatment, respectively. Lentivirus transfection was used to overexpress PRKCA. H&E staining and lung injury in CLP-surgery mice were evaluated. Gene expression was evaluated using qPCR and Western blotting. The expression of TNF-α, IL-1β, and IL-6 was examined using qPCR and ELISA. The expression of LC3 and TOM20 was evaluated using immunofluorescence assays. Cell apoptosis was assessed using a flow cytometry assay. The bond between miR-15a-5p and PDK4 was confirmed by dual-luciferase reporter gene and RNA immunoprecipitation assays. In vivo and in vitro, PRKCA overexpression reduced lung injury to prompt mitophagy and inhibit the inflammatory response, ROS production, and cell apoptosis. miR-15a-5p was highly expressed in macrophages treated with LPS/IFN-γ and was negatively mediated by PRKCA. The overexpression of miR-15a-5p reduced the effects of PRKCA upregulation in macrophages. miR-15a-5p could restrain mitophagy in LPS/IFN-γ-treated macrophages by directly targeting PDK4. Furthermore, PDK4 knockdown reversed the inhibition of cell apoptosis and inflammatory factor release caused by miR-15a-5p silencing. The PRKCA/miR-15a-5p/PDK4 axis alleviated ALI caused by sepsis by promoting mitophagy and repressing anti-inflammatory response.

Crosstalk between CD4+ T Cells and Airway Smooth Muscle in Pediatric Obesity-related Asthma.

Rationale: Pediatric obesity-related asthma is a nonatopic asthma phenotype with high disease burden and few effective therapies. RhoGTPase upregulation in peripheral blood T helper (Th) cells is associated with the phenotype, but the mechanisms that underlie this association are not known. Objectives: To investigate the mechanisms by which upregulation of CDC42 (Cell Division Cycle 42), a RhoGTPase, in Th cells is associated with airway smooth muscle (ASM) biology. Methods: Chemotaxis of obese asthma and healthy-weight asthma Th cells, and their adhesion to obese and healthy-weight nonasthmatic ASM, was investigated. Transcriptomics and proteomics were used to determine the differential effect of obese and healthy-weight asthma Th cell adhesion to obese or healthy-weight ASM biology. Measurements and Main Results: Chemotaxis of obese asthma Th cells with CDC42 upregulation was resistant to CDC42 inhibition. Obese asthma Th cells were more adherent to obese ASM compared with healthy-weight asthma Th cells to healthy-weight ASM. Compared with coculture with healthy-weight ASM, obese asthma Th cell coculture with obese ASM was positively enriched for genes and proteins involved in actin cytoskeleton organization, transmembrane receptor protein kinase signaling, and cell mitosis, and negatively enriched for extracellular matrix organization. Targeted gene evaluation revealed upregulation of IFNG, TNF (tumor necrosis factor), and Cluster of Differentiation 247 (CD247) among Th cell genes, and of Ak strain transforming (AKT), Ras homolog family member A (RHOA), and CD38, with downregulation of PRKCA (Protein kinase C-alpha), among smooth muscle genes. Conclusions: Obese asthma Th cells have uninhibited chemotaxis and are more adherent to obese ASM, which is associated with upregulation of genes and proteins associated with smooth muscle proliferation and reciprocal nonatopic Th cell activation.

Precision Medicine in Patients with Differential Diabetic Phenotypes: Novel Opportunities from Network Medicine

Diabetes mellitus (DM) comprises differential clinical phenotypes ranging from rare monogenic to common polygenic forms, such as type 1 (T1DM), type 2 (T2DM), and gestational diabetes, which are associated with cardiovascular complications. Also, the high- -risk prediabetic state is rising worldwide, suggesting the urgent need for early personalized strategies to prevent and treat a hyperglycemic state. We aim to discuss the advantages and challenges of Network Medicine approaches in clarifying disease-specific molecular pathways, which may open novel ways for repurposing approved drugs to reach diabetes precision medicine and personalized therapy. The interactome or protein-protein interactions (PPIs) is a useful tool to identify subtle molecular differences between precise diabetic phenotypes and predict putative novel drugs. Despite being previously unappreciated as T2DM determinants, the growth factor receptor-bound protein 14 (GRB14), calmodulin 2 (CALM2), and protein kinase C-alpha (PRKCA) might have a relevant role in disease pathogenesis. Besides, in silico platforms have suggested that diflunisal, nabumetone, niflumic acid, and valdecoxib may be suitable for the treatment of T1DM; phenoxybenzamine and idazoxan for the treatment of T2DM by improving insulin secretion; and hydroxychloroquine reduce the risk of coronary heart disease (CHD) by counteracting inflammation. Network medicine has the potential to improve precision medicine in diabetes care and enhance personalized therapy. However, only randomized clinical trials will confirm the clinical utility of network- oriented biomarkers and drugs in the management of DM.

PATAS, a First-in-Class Therapeutic Peptide Biologic, Improves Whole-Body Insulin Resistance and Associated Comorbidities In Vivo

Adipose tissue is a key regulator of whole-body metabolic fitness because of its role in controlling insulin sensitivity. Obesity is associated with hypertrophic adipocytes with impaired glucose absorption, a phenomenon existing in the ultrarare monogenic disorder Alström syndrome consisting of severe insulin resistance. Inactivation of ALMS1 directly inhibits insulin-mediated glucose absorption in the white adipose tissue and induces severe insulin resistance, which leads to type 2 diabetes, accelerated nonalcoholic liver disease, and fibrosis. These phenotypes were reversed by specific adipocyte-ALMS1 reactivation in vivo. Subsequently, ALMS1 was found to bind to protein kinase C-α (PKCα) in the adipocyte, and upon insulin signaling, PKCα is released from ALMS1. α-Helices in the kinase domain of PKCα were therefore screened to identify a peptide sequence that interfered with the ALMS1-PKCα protein interaction. When incubated with cultured human adipocytes, the stapled peptide termed PATAS, for Peptide derived of PKC Alpha Targeting AlmS, triggered insulin-independent glucose absorption, de novo lipogenesis, and cellular glucose utilization. In vivo, PATAS reduced whole-body insulin resistance, and improved glucose intolerance, fasting glucose, liver steatosis, and fibrosis in rodents. Thus, PATAS represents a novel first-in-class peptide that targets the adipocyte to ameliorate insulin resistance and its associated comorbidities.

Activated protein kinase C-alpha as a simple test for urothelial cancer screening.

e16552 Background: The development of a non-invasive, highly predictive diagnostic test for urothelial cancer (UC) would greatly benefit patients. Although numerous urine-based tests have been developed, it is not widely used, except for urine cytology, due to insufficient sensitivity, negative predictive value and high cost. Previously we reported that protein kinase C-alpha (PKCα) is overexpressed or activated in several cancer tissues but not in normal tissue, and we developed an activated PKCα-specific peptide substrate (FKKQGSFAKKK; Patent No. 5476559). The purpose of this study was to investigate the potential for UC screening of simple test detecting activated PKCα. Methods: This institutional review board-approved prospective study included patients with bladder cancer or upper urinary tract UC who underwent surgery at Kyushu University Hospital between September 2018 and December 2020. Patients with benign urologic disorders or healthy volunteers were included as a control group. Patients with prostate cancer (PC) or renal cell carcinoma (RCC) who underwent curative surgery were included as other genitourinary (GU) cancer group. Patients with other coexisting malignant tumors were excluded. Urine samples were collected prior to surgery, 20 mL of urine was centrifuged, and the pellet was lysed for analysis. We evaluated the phosphorylation status of the activated PKCα-specific peptide substrate by MALDI-TOF mass spectrometry. The utility of activated PKCα as a urinary biomarker was evaluated by its sensitivity and negative predictive value when compared to control group or other GU cancers group. Results: Urine samples were obtained from 226 individuals, which included 98 patients with UC, 51 with other GU caners, and 77 with control group. Of the 98 patients with UC, activated PKCα was detected in 75 patients, with sensitivity of 76.5%. The sensitivity in patients with high-grade and low-grade UC were 84% and 62%, respectively. The sensitivity in those with high-grade UC increased to 93% when combined with urine cytology. On the other hand, activated PKCα were rarely detected in non-UC patients which includes other GU cancers group and control group. The specificity among the non-UC patients was 74.2%. In the comparison between patients with UC and non-UC, the negative predictive value of activated PKCα was 80.5%. The area under the receiver operating characteristic curve (AUC) for detecting UC of activated PKCα was 0.80. Conclusions: This study demonstrates the utility of activated PKCα as a novel urine screening test for UC. (Patent Application No. PCT/JP2020/045257) Since this test is based on a single target, inexpensive detection devices can be developed.

Programmed Exercise Attenuates Familial Hypertrophic Cardiomyopathy in Transgenic E22K Mice via Inhibition of PKC-α/NFAT Pathway.

Familial hypertrophic cardiomyopathy (FHCM), an autosomal dominant disease, is caused by mutations in genes encoding cardiac sarcomeric proteins. E22K, a mutation in the myosin regulatory light chain sarcomere gene, is associated with the development of FHCM. However, the molecular mechanisms by which E22K mutation promotes septal hypertrophy are still elusive. The hypertrophic markers, including beta-myosin heavy chain, atrial natriuretic peptide and B-type natriuretic peptide, were upregulated, as detected by fluorescence quantitative PCR. The gene expression profiles were greatly altered in the left ventricle of E22K mutant mice. Among these genes, nuclear factor of activated T cells (NFAT) and protein kinase C-alpha (PKC-α) were upregulated, and their protein expression levels were also verified to be elevated. The fibrosis markers, such as phosphorylated Smad and transforming growth factor beta receptor, were also elevated in transgenic E22K mice. After receiving 6 weeks of procedural exercise training, the expression levels of PKC-α and NFAT were reversed in E22K mouse hearts. In addition, the expression levels of several fibrosis-related genes such as transforming growth factor beta receptor 1, Smad4, and alpha smooth muscle actin in E22K mouse hearts were also reversed. Genes that associated with cardiac remodeling such as myocyte enhancer factor 2C, extracellular matrix protein 2 and fibroblast growth factor 12 were reduced after exercising. Taken together, our results indicate that exercise can improve hypertrophy and fibrosis-related indices in transgenic E22K mice via PKC-α/NFAT pathway, which provide new insight into the prevention and treatment of familial hypertrophic cardiomyopathy.

Rno_circ_0001004 Acts as a miR-709 Molecular Sponge to Regulate the Growth Hormone Synthesis and Cell Proliferation.

(1) Background: As a novel type of non-coding RNA with a stable closed-loop structure, circular RNA (circRNA) can interact with microRNA (miRNA) and influence the expression of miRNA target genes. However, circRNA involved in pituitary growth hormone (GH) regulation is poorly understood. Our previous study revealed protein kinase C alpha (PRKCA) as the target gene of miR-709. Currently, the expression and function of rno_circRNA_0001004 in the rat pituitary gland is not clarified; (2) Methods: In this study, both bioinformatics analysis and dual-luciferase report assays showed a target relationship between rno_circRNA_0001004 and miR-709. Furthermore, the rno_circRNA_0001004 overexpression vector and si-circ_0001004 were constructed and transfected into GH3 cells; (3) Results: We found that rno_circRNA_0001004 expression was positively correlated with the PRKCA gene and GH expression levels, while it was negatively correlated with miR-709. In addition, overexpression of rno-circ_0001004 also promoted proliferation and relieved the inhibition of miR-709 in GH3 cells; (4) Conclusions: Our findings show that rno_circ_0001004 acts as a novel sponge for miR-709 to regulate GH synthesis and cell proliferation, and are the first case of discovery of the regulatory role of circRNA_0001004 in pituitary GH.

Connexin32 ameliorates epithelial-to-mesenchymal-transition in diabetic renal tubular via inhibiting NOX4

Renal tubulointerstitial fibrosis (RIF), characterized by epithelial-to-mesenchymal transition (EMT) of renal tubular epithelial cells (TECs), is the main cause of diabetic renal fibrosis. Oxidative stress plays a pivotal role in the development of diabetic RIF. Connexin32 (Cx32), prominently expressed in renal TECs, has emerged as an important player in the regulation of oxidative stress. However, the role of Cx32 in diabetic RIF has not been explored yet. Here, we showed that adenovirus-mediated Cx32 overexpression suppressed EMT to ameliorate RIF and renal function in STZ-induced diabetic mice, while knockout (KO) of Cx32 exacerbated RIF in diabetic mice. Moreover, overexpression of Cx32 inhibited EMT and the production of extra cellular matrix (ECM) in high glucose (HG) induced NRK-52E cells, whereas knockdown of Cx32 showed the opposite effects. Furthermore, we showed that NOX4, the main source of ROS in renal tubular, was down-regulated by Cx32. Mechanistically, Cx32 down-regulated the expression of PKC alpha in a carboxyl-terminal-dependent manner, thereby inhibiting the phosphorylation at Thr147 of p22phox triggered by PKC alpha, which ultimately repressed the formation of the p22phox-NOX4 complex to reduce the protein level of NOX4. Thus, we establish Cx32 as a novel target and confirm the protection mechanism in RIF.

Novel noninvasive marker of regression of clear cell renal cell carcinoma (ccRCC).

Analyzing protein kinase C (PKC) alpha, iota, and zeta as well as levels of Mxi-2 and Vim3 in regressive clear cell renal carcinomas (ccRCCs) and urine samples. Fresh samples of ccRCCs (predominantly pT1a/b) with different degrees of regression (<10%, 30%, 50%, and 70%) vs normal renal tissue and oncocytomas were studied by Western blot, using antibodies of different PKC isoforms. Urine samples from these tumors were analyzed by ELISA (PKC isoforms, Mxi-2, and Vim3). With increasing degree of regression beyond 10%, nuclear Mxi-2 and Vim3 were highly overexpressed in fresh tumor samples. In urine samples, Vim3 was significantly overexpressed in oncocytoma and downregulated in RCCs with 70% regression. Western blot analysis shows that PKC alpha and iota levels were significantly increased in fresh tumor tissue samples (tumors with 30% regression). PKC zeta was expressed in normal kidney and significantly increased in oncocytoma but not found in ccRCCs. In patients' urines, Mxi-2 was significantly reduced (regression > 50%), while PKC isoform alpha was significantly increased by advanced regression rate. PKC iota in patients' urine was overexpressed in oncocytoma and reduced in all ccRCC urines. Tumor regression in ccRCC tissue shows strong nuclear overexpression of Mxi-2, Vim3, and PKC alpha and iota. In respective urines, PKC alpha was overexpressed; PKC iota was decreased. Mxi-2 and Vim3 decreased with increasing regression rates. These reagents could serve as noninvasive ccRCC markers for regression.

Insights into the potential of withanolides as Phosphodiesterase-4 (PDE4D) inhibitors

Medicinal herbs have been used as traditional medicines for centuries. The molecular mechanism of action of their bioactive molecules against various diseases or therapeutic targets is still being explored. Here, the active compounds (withanolides) of a well-known Indian medicinal herb, Ashwagandha (Withania somnifera), have been studied for their most potential therapeutic targets and their mechanism of action using ligand-based screening and receptor-based approaches. Ligand-based screening predicted the six top therapeutic targets, namely, Protein kinase C alpha (PRKCA), Protein kinase C delta (PRKCD), Protein kinase C epsilon (PRKCE), Androgenic Receptor (AR), Cycloxygenase-2 (PTGS-2) and Phosphodiesterase-4D (PDE4D). Further, when these predictions were validated using receptor-based studies, i.e. molecular docking, molecular dynamics simulation and free energy calculations, it was found that PDE4D was the most potent target for four withanolides, namely, Withaferin-A, 17-Hydroxywithaferin-A, 27-Hydroxywithanone and Withanolide-R. These compounds had a better binding affinity and similar interactions as that of an already known inhibitor (Zardaverine) of PDE4D. These results warrant further in-vitro and in-vivo investigations to examine their therapeutic potential as an inhibitor of PDE4D. Communicated by Ramaswamy H. Sarma

Fetal malnutrition is associated with impairment of endogenous melatonin synthesis in pineal via hypermethylation of promoters of protein kinase C alpha and cAMP response element-binding.

This study investigated whether and how fetal malnutrition would influence endogenous melatonin synthesis, and whether such effect of fetal malnutrition would transmit to the next generation. We enrolled 2466 participants and 1313 of their offspring. The urine 6-hydroxymelatonin sulfate and serum melatonin rhythm were measured. Methylationmicroarray detection and bioinformatics analysis were performed to identify hub methylated sites. Additionally, rat experiment was performed to elucidate mechanisms. The participants with fetal malnutrition had lower 6-hydroxymelatonin sulfate (16.59±10.12μg/24hours vs 24.29±11.99μg/24hours, P<.001) and arear under curve of melatonin rhythm (67.11±8.16pg/mL vs 77.11±8.04pg/mL, P<.001). We identified 961 differentially methylated sites, in which the hub methylated sites were locating on protein kinase C alpha (PRKCA) and cAMP response element-binding protein (CREB1) promoters, mediating the association of fetal malnutrition with impaired melatonin secretion. However, such effects were not observed in the offspring (all P>.05). Impaired histomorphology of pineal, decreased melatonin in serum, pineal, and pinealocyte were also found in the in vivo and in vitro experiments (P<.05 for the differences of the indicators). Hypermethylation of 10 CpG sites on the PRKCA promoter and 8 CpG sites on the CREB1 promoter were identified (all P<.05), which down-regulated PRKCA and CREB1 expressions, leading to decreased expression of AANAT, and then resulting in the impaired melatonin synthesis. Collectively, fetal malnutrition can impair melatonin synthesis through hypermethylation of PRKCA and CREB1 promoters, and such effects cannot be transmitted to the next generation.

Syndecan-4 in Tumor Cell Motility.

Simple SummaryCell migration is crucial fReaor metastasis formation and a hallmark of malignancy. The primary cause of high mortality among oncology patients is the ability of cancer cells to metastasize. To form metastasis, primary tumor cells must be intrinsically able to move. The transmembrane, heparan sulfate proteoglycan syndecan-4 (SDC4) exhibits multiple functions in signal transduction by regulating Rac1 GTPase activity and consequently actin remodeling, as well as regulating focal adhesion kinase, protein kinase C-alpha and the level of intracellular calcium. By affecting several signaling pathways and biological processes, SDC4 is involved in cell migration under physiological and pathological conditions as well. In this review, we discuss the SDC4-mediated cell migration focusing on the role of SDC4 in tumor cell movement.Syndecan-4 (SDC4) is a ubiquitously expressed, transmembrane proteoglycan bearing heparan sulfate chains. SDC4 is involved in numerous inside-out and outside-in signaling processes, such as binding and sequestration of growth factors and extracellular matrix components, regulation of the activity of the small GTPase Rac1, protein kinase C-alpha, the level of intracellular calcium, or the phosphorylation of focal adhesion kinase. The ability of this proteoglycan to link the extracellular matrix and actin cytoskeleton enables SDC4 to contribute to biological functions like cell adhesion and migration, cell proliferation, cytokinesis, cellular polarity, or mechanotransduction. The multiple roles of SDC4 in tumor pathogenesis and progression has already been demonstrated; therefore, the expression and signaling of SDC4 was investigated in several tumor types. SDC4 influences tumor progression by regulating cell proliferation as well as cell migration by affecting cell-matrix adhesion and several signaling pathways. Here, we summarize the general role of SDC4 in cell migration and tumor cell motility.

Circulating Plasma miRNA and Clinical/Hemodynamic Characteristics Provide Additional Predictive Information About Acute Pulmonary Thromboembolism, Chronic Thromboembolic Pulmonary Hypertension and Idiopathic Pulmonary Hypertension.

Idiopathic pulmonary artery hypertension (IPAH), chronic thromboembolic pulmonary hypertension (CTEPH), and acute pulmonary embolism (APTE) are life-threatening cardiopulmonary diseases without specific surgical or medical treatment. Although APTE, CTEPH and IPAH are different pulmonary vascular diseases in terms of clinical presentation, prevalence, pathophysiology and prognosis, the identification of their circulating microRNA (miRNAs) might help in recognizing differences in their outcome evolution and clinical forms. The aim of this study was to describe the APTE, CTEPH, and IPAH-associated miRNAs and to predict their target genes. The target genes of the key differentially expressed miRNAs were analyzed, and functional enrichment analyses were carried out. The miRNAs were detected using RT-PCR. Finally, we incorporated plasma circulating miRNAs in baseline and clinical characteristics of the patients to detect differences between APTE and CTEPH in time of evolution, and differences between CTEPH and IPAH in diseases form. We found five top circulating plasma miRNAs in common with APTE, CTEPH and IPAH assembled in one conglomerate. Among them, miR-let-7i-5p expression was upregulated in APTE and IPAH, while miRNA-320a was upregulated in CTEP and IPAH. The network construction for target genes showed 11 genes regulated by let-7i-5p and 20 genes regulated by miR-320a, all of them regulators of pulmonary arterial adventitial fibroblasts, pulmonary artery endothelial cell, and pulmonary artery smooth muscle cells. AR (androgen receptor), a target gene of hsa-let-7i-5p and has-miR-320a, was enriched in pathways in cancer, whereas PRKCA (Protein Kinase C Alpha), also a target gene of hsa-let-7i-5p and has-miR-320a, was enriched in KEGG pathways, such as pathways in cancer, glioma, and PI3K-Akt signaling pathway. We inferred that CTEPH might be the consequence of abnormal remodeling in APTE, while unbalance between the hyperproliferative and apoptosis-resistant phenotype of pulmonary arterial adventitial fibroblasts, pulmonary artery endothelial cell and pulmonary artery smooth muscle cells in pulmonary artery confer differences in IPAH and CTEPH diseases form. We concluded that the incorporation of plasma circulating let-7i-5p and miRNA-320a in baseline and clinical characteristics of the patients reinforces differences between APTE and CTEPH in outcome evolution, as well as differences between CTEPH and IPAH in diseases form.